Commit fc1b6d6d authored by Tuong Lien's avatar Tuong Lien Committed by David S. Miller
Browse files

tipc: introduce TIPC encryption & authentication 



This commit offers an option to encrypt and authenticate all messaging,
including the neighbor discovery messages. The currently most advanced
algorithm supported is the AEAD AES-GCM (like IPSec or TLS). All
encryption/decryption is done at the bearer layer, just before leaving
or after entering TIPC.

Supported features:
- Encryption & authentication of all TIPC messages (header + data);
- Two symmetric-key modes: Cluster and Per-node;
- Automatic key switching;
- Key-expired revoking (sequence number wrapped);
- Lock-free encryption/decryption (RCU);
- Asynchronous crypto, Intel AES-NI supported;
- Multiple cipher transforms;
- Logs & statistics;

Two key modes:
- Cluster key mode: One single key is used for both TX & RX in all
nodes in the cluster.
- Per-node key mode: Each nodes in the cluster has one specific TX key.
For RX, a node requires its peers' TX key to be able to decrypt the
messages from those peers.

Key setting from user-space is performed via netlink by a user program
(e.g. the iproute2 'tipc' tool).

Internal key state machine:

                                 Attach    Align(RX)
                                     +-+   +-+
                                     | V   | V
        +---------+      Attach     +---------+
        |  IDLE   |---------------->| PENDING |(user = 0)
        +---------+                 +---------+
           A   A                   Switch|  A
           |   |                         |  |
           |   | Free(switch/revoked)    |  |
     (Free)|   +----------------------+  |  |Timeout
           |              (TX)        |  |  |(RX)
           |                          |  |  |
           |                          |  v  |
        +---------+      Switch     +---------+
        | PASSIVE |<----------------| ACTIVE  |
        +---------+       (RX)      +---------+
        (user = 1)                  (user >= 1)

The number of TFMs is 10 by default and can be changed via the procfs
'net/tipc/max_tfms'. At this moment, as for simplicity, this file is
also used to print the crypto statistics at runtime:

echo 0xfff1 > /proc/sys/net/tipc/max_tfms

The patch defines a new TIPC version (v7) for the encryption message (-
backward compatibility as well). The message is basically encapsulated
as follows:

   +----------------------------------------------------------+
   | TIPCv7 encryption  | Original TIPCv2    | Authentication |
   | header             | packet (encrypted) | Tag            |
   +----------------------------------------------------------+

The throughput is about ~40% for small messages (compared with non-
encryption) and ~9% for large messages. With the support from hardware
crypto i.e. the Intel AES-NI CPU instructions, the throughput increases
upto ~85% for small messages and ~55% for large messages.

By default, the new feature is inactive (i.e. no encryption) until user
sets a key for TIPC. There is however also a new option - "TIPC_CRYPTO"
in the kernel configuration to enable/disable the new code when needed.

MAINTAINERS | add two new files 'crypto.h' & 'crypto.c' in tipc

Acked-by: default avatarYing Xue <ying.xue@windreiver.com>
Acked-by: default avatarJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: default avatarTuong Lien <tuong.t.lien@dektech.com.au>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 134bdac3

net/tipc/Kconfig

+15 −0
Original line number Diff line number Diff line
@@ -35,6 +35,21 @@ config TIPC_MEDIA_UDP 
	  Saying Y here will enable support for running TIPC over IP/UDP

	bool

	default y

config TIPC_CRYPTO

	bool "TIPC encryption support"

	depends on TIPC

	select CRYPTO

	select CRYPTO_AES

	select CRYPTO_GCM

	help

	  Saying Y here will enable support for TIPC encryption.

	  All TIPC messages will be encrypted/decrypted by using the currently most

	  advanced algorithm: AEAD AES-GCM (like IPSec or TLS) before leaving/

	  entering the TIPC stack.

	  Key setting from user-space is performed via netlink by a user program

	  (e.g. the iproute2 'tipc' tool).

	bool

	default y



config TIPC_DIAG

	tristate "TIPC: socket monitoring interface"

net/tipc/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ CFLAGS_trace.o += -I$(src) 
tipc-$(CONFIG_TIPC_MEDIA_UDP)	+= udp_media.o

tipc-$(CONFIG_TIPC_MEDIA_IB)	+= ib_media.o

tipc-$(CONFIG_SYSCTL)		+= sysctl.o

tipc-$(CONFIG_TIPC_CRYPTO)	+= crypto.o





obj-$(CONFIG_TIPC_DIAG)	+= diag.o

net/tipc/bcast.c

+1 −1
Original line number Diff line number Diff line
@@ -84,7 +84,7 @@ static struct tipc_bc_base *tipc_bc_base(struct net *net) 
 */

int tipc_bcast_get_mtu(struct net *net)

{

	return tipc_link_mtu(tipc_bc_sndlink(net)) - INT_H_SIZE;

	return tipc_link_mss(tipc_bc_sndlink(net));

}



void tipc_bcast_disable_rcast(struct net *net)

net/tipc/bearer.c

+27 −8
Original line number Diff line number Diff line
@@ -44,6 +44,7 @@ 
#include "netlink.h"

#include "udp_media.h"

#include "trace.h"

#include "crypto.h"



#define MAX_ADDR_STR 60
@@ -516,10 +517,15 @@ void tipc_bearer_xmit_skb(struct net *net, u32 bearer_id, 


	rcu_read_lock();

	b = bearer_get(net, bearer_id);

	if (likely(b && (test_bit(0, &b->up) || msg_is_reset(hdr))))

	if (likely(b && (test_bit(0, &b->up) || msg_is_reset(hdr)))) {

#ifdef CONFIG_TIPC_CRYPTO

		tipc_crypto_xmit(net, &skb, b, dest, NULL);

		if (skb)

#endif

			b->media->send_msg(net, skb, b, dest);

	else

	} else {

		kfree_skb(skb);

	}

	rcu_read_unlock();

}
@@ -527,7 +533,8 @@ void tipc_bearer_xmit_skb(struct net *net, u32 bearer_id, 
 */

void tipc_bearer_xmit(struct net *net, u32 bearer_id,

		      struct sk_buff_head *xmitq,

		      struct tipc_media_addr *dst)

		      struct tipc_media_addr *dst,

		      struct tipc_node *__dnode)

{

	struct tipc_bearer *b;

	struct sk_buff *skb, *tmp;
@@ -541,11 +548,16 @@ void tipc_bearer_xmit(struct net *net, u32 bearer_id, 
		__skb_queue_purge(xmitq);

	skb_queue_walk_safe(xmitq, skb, tmp) {

		__skb_dequeue(xmitq);

		if (likely(test_bit(0, &b->up) || msg_is_reset(buf_msg(skb))))

		if (likely(test_bit(0, &b->up) || msg_is_reset(buf_msg(skb)))) {

#ifdef CONFIG_TIPC_CRYPTO

			tipc_crypto_xmit(net, &skb, b, dst, __dnode);

			if (skb)

#endif

				b->media->send_msg(net, skb, b, dst);

		else

		} else {

			kfree_skb(skb);

		}

	}

	rcu_read_unlock();

}
@@ -555,6 +567,7 @@ void tipc_bearer_bc_xmit(struct net *net, u32 bearer_id, 
			 struct sk_buff_head *xmitq)

{

	struct tipc_net *tn = tipc_net(net);

	struct tipc_media_addr *dst;

	int net_id = tn->net_id;

	struct tipc_bearer *b;

	struct sk_buff *skb, *tmp;
@@ -569,7 +582,12 @@ void tipc_bearer_bc_xmit(struct net *net, u32 bearer_id, 
		msg_set_non_seq(hdr, 1);

		msg_set_mc_netid(hdr, net_id);

		__skb_dequeue(xmitq);

		b->media->send_msg(net, skb, b, &b->bcast_addr);

		dst = &b->bcast_addr;

#ifdef CONFIG_TIPC_CRYPTO

		tipc_crypto_xmit(net, &skb, b, dst, NULL);

		if (skb)

#endif

			b->media->send_msg(net, skb, b, dst);

	}

	rcu_read_unlock();

}
@@ -596,6 +614,7 @@ static int tipc_l2_rcv_msg(struct sk_buff *skb, struct net_device *dev, 
	if (likely(b && test_bit(0, &b->up) &&

		   (skb->pkt_type <= PACKET_MULTICAST))) {

		skb_mark_not_on_list(skb);

		TIPC_SKB_CB(skb)->flags = 0;

		tipc_rcv(dev_net(b->pt.dev), skb, b);

		rcu_read_unlock();

		return NET_RX_SUCCESS;

net/tipc/bearer.h

+2 −1
Original line number Diff line number Diff line
@@ -232,7 +232,8 @@ void tipc_bearer_xmit_skb(struct net *net, u32 bearer_id, 
			  struct tipc_media_addr *dest);

void tipc_bearer_xmit(struct net *net, u32 bearer_id,

		      struct sk_buff_head *xmitq,

		      struct tipc_media_addr *dst);

		      struct tipc_media_addr *dst,

		      struct tipc_node *__dnode);

void tipc_bearer_bc_xmit(struct net *net, u32 bearer_id,

			 struct sk_buff_head *xmitq);

void tipc_clone_to_loopback(struct net *net, struct sk_buff_head *pkts);

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